In my (very personal) opinion, the fact that not many people, comparatively speaking, are fluent in any language other than the local languages and a certain level of short sightedness that makes us look only to local markets[1] has much more to do today than the dark ages of the dictatorship.
I moved out of Spain more than a decade ago and things seem to be changing (at least now I find spanish products in my local supermarket that I had to bring in my luggage before when I went for a visit), but we are late to the game and it will take time to catch up.
[0] Well, -ish
[1] Not exclusively a Spanish fault... Many countries suffer this to certain level.